iTETRIS Platform Architecture for the Integration of Cooperative Traffic and Wireless Simulations

The use of cooperative wireless communications can support driving through dynamic exchange of Vehicle-to-Vehicle (V2V) and Vehicle-to-Infrastructure (V2I) messages. Traffic applications based on such systems will be able to generate a safer, faster, cheaper and cleaner way for people and goods to move. In this context, the iTERIS project aims at providing the framework to combine traffic mobility and wireless communication simulations for large scale testing of traffic management solutions based on cooperative systems. This paper addresses the description and explanation of the implementation choices taken to build a modular and interoperable architecture integrating heterogeneous traffic and wireless simulators, and application algorithms supporting traffic management strategies. The functions of an “in-between” control system for managing correct simulation executions over the platform are presented. The inter-block interaction procedures identified to ensure optimum data transfer for simulation efficiency are also introduced

Clock synchronisation for UWB and DECT communication networks

Synchronisation deals with the distribution of time and/or frequency across a network of nodes dispersed in an area, in order to align their clocks with respect to time and/or frequency. It remains an important requirement in telecommunication networks, especially in Time Division Duplexing (TDD) systems such as Ultra Wideband (UWB) and Digital Enhanced Cordless Telecommunications (DECT) systems. This thesis explores three di erent research areas related to clock synchronisation in communication networks; namely algorithm development and implementation, managing Packet Delay Variation (PDV), and coping with the failure of a master node. The first area proposes a higher-layer synchronisation algorithm in order to meet the specific requirements of a UWB network that is based on the European Computer Manufacturers Association (ECMA) standard. At up to 480 Mbps data rate, UWB is an attractive technology for multimedia streaming. Higher-layer synchronisation is needed in order to facilitate synchronised playback at the receivers and prevent distortion, but no algorithm is de ned in the ECMA-368 standard. In this research area, a higher-layer synchronisation algorithm is developed for an ECMA-368 UWB network. Network simulations and FPGA implementation are used to show that the new algorithm satis es the requirements of the network. The next research area looks at how PDV can be managed when Precision Time Protocol (PTP) is implemented in an existing Ethernet network. Existing literature indicates that the performance of a PDV ltering algorithm usually depends on the delay pro le of the network in which it is applied. In this research area, a new sample-mode PDV filter is proposed which is independent of the shape of the delay profile. Numerical simulations show that the sample-mode filtering algorithm is able to match or out-perform the existing sample minimum, mean, and maximum filters, at differentlevels of network load. Finally, the thesis considers the problem of dealing with master failures in a PTP network for a DECT audio application. It describes the existing master redundancy techniques and shows why they are unsuitable for the specific application. Then a new alternate master cluster technique is proposed along with an alternative BMCA to suit the application under consideration. Network simulations are used to show how this technique leads to a reduction in the total time to recover from a master failure

Bio-Inspired Tools for a Distributed Wireless Sensor Network Operating System

The problem which I address in this thesis is to find a way to organise and manage a network of wireless sensor nodes using a minimal amount of communication. To find a solution I explore the use of Bio-inspired protocols to enable WSN management while maintaining a low communication overhead. Wireless Sensor Networks (WSNs) are loosely coupled distributed systems comprised of low-resource, battery powered sensor nodes. The largest problem with WSN management is that communication is the largest consumer of a sensor node’s energy. WSN management systems need to use as little communication as possible to prolong their operational lifetimes. This is the Wireless Sensor Network Management Problem. This problem is compounded because current WSN management systems glue together unrelated protocols to provide system services causing inter-protocol interference. Bio-inspired protocols provide a good solution because they enable the nodes to self-organise, use local area communication, and can combine their communication in an intelligent way with minimal increase in communication. I present a combined protocol and MAC scheduler to enable multiple service protocols to function in a WSN at the same time without causing inter-protocol interference. The scheduler is throughput optimal as long as the communication requirements of all of the protocols remain within the communication capacity of the network. I show that the scheduler improves a dissemination protocol’s performance by 35%. A bio-inspired synchronisation service is presented which enables wireless sensor nodes to self organise and provide a time service. Evaluation of the protocol shows an 80% saving in communication over similar bio-inspired synchronisation approaches. I then add an information dissemination protocol, without significantly increasing communication. This is achieved through the ability of our bio-inspired algorithms to combine their communication in an intelligent way so that they are able to offer multiple services without requiring a great deal of inter-node communication.Open Acces

Bioans: bio-inspired ambient intelligence protocol for wireless sensor networks

This paper describes the BioANS (Bio-inspired Autonomic Networked Services) protocol that uses a novel utility-based service selection mechanism to drive autonomicity in sensor networks. Due to the increase in complexity of sensor network applications, self-configuration abilities, in terms of service discovery and automatic negotiation, have become core requirements. Further, as such systems are highly dynamic due to mobility and/or unreliability; runtime self-optimisation and self-healing is required. However the mechanism to implement this must be lightweight due to the sensor nodes being low in resources, and scalable as some applications can require thousands of nodes. BioANS incorporates some characteristics of natural emergent systems and these contribute to its overall stability whilst it remains simple and efficient. We show that not only does the BioANS protocol implement autonomicity in allowing a dynamic network of sensors to continue to function under demanding circumstances, but that the overheads incurred are reasonable. Moreover, state-flapping between requester and provider, message loss and randomness are not only tolerated but utilised to advantage in the new protocol

Development and implementation of a LabVIEW based SCADA system for a meshed multi-terminal VSC-HVDC grid scaled platform

This project is oriented to the development of a Supervisory, Control and Data Acquisition (SCADA) software to control and supervise electrical variables from a scaled platform that represents a meshed HVDC grid employing National Instruments hardware and LabVIEW logic environment. The objective is to obtain real time visualization of DC and AC electrical variables and a lossless data stream acquisition. The acquisition system hardware elements have been configured, tested and installed on the grid platform. The system is composed of three chassis, each inside of a VSC terminal cabinet, with integrated Field-Programmable Gate Arrays (FPGAs), one of them connected via PCI bus to a local processor and the rest too via Ethernet through a switch. Analogical acquisition modules were A/D conversion takes place are inserted into the chassis. A personal computer is used as host, screen terminal and storing space. There are two main access modes to the FPGAs through the real time system. It has been implemented a Scan mode VI to monitor all the grid DC signals and a faster FPGA access mode VI to monitor one converter AC and DC values. The FPGA application consists of two tasks running at different rates and a FIFO has been implemented to communicate between them without data loss. Multiple structures have been tested on the grid platform and evaluated, ensuring the compliance of previously established specifications, such as sampling and scanning rate, screen refreshment or possible data loss. Additionally a turbine emulator was implemented and tested in Labview for further testing

Optimising lower layers of the protocol stack to improve communication performance in a wireless temperature sensor network

The function of wireless sensor networks is to monitor events or gather information and report the information to a sink node, a central location or a base station. It is a requirement that the information is transmitted through the network efficiently. Wireless communication is the main activity that consumes energy in wireless sensor networks through idle listening, overhearing, interference and collision. It becomes essential to limit energy usage while maintaining communication between the sensor nodes and the sink node as the nodes die after the battery has been exhausted. Thus, conserving energy in a wireless sensor network is of utmost importance. Numerous methods to decrease energy expenditure and extend the lifetime of the network have been proposed. Researchers have devised methods to efficiently utilise the limited energy available for wireless sensor networks by optimising the design parameters and protocols. Cross-layer optimisation is an approach that has been employed to improve wireless communication. The essence of cross-layer scheme is to optimise the exchange and control of data between two or more layers to improve efficiency. The number of transmissions is therefore a vital element in evaluating overall energy usage. In this dissertation, a Markov Chain model was employed to analyse the tuning of two layers of the protocol stack, namely the Physical Layer (PHY) and Media Access Control layer (MAC), to find possible energy gains. The study was conducted utilising the IEEE 802.11 channel, SensorMAC (SMAC) and Slotted-Aloha (S-Aloha) medium access protocols in a star topology Wireless Temperature Sensor Network (WTSN). The research explored the prospective energy gains that could be realised through optimizing the Forward Error Correction (FEC) rate. Different Reed Solomon codes were analysed to explore the effect of protocol tuning on energy efficiency, namely transmission power, modulation method, and channel access. The case where no FEC code was used and analysed as the control condition. A MATLAB simulation model was used to identify the statistics of collisions, overall packets transmitted, as well as the total number of slots used during the transmission phase. The bit error probability results computed analytically were utilised in the simulation model to measure the probability of successful transmitting data in the physical layer. The analytical values and the simulation results were compared to corroborate the correctness of the models. The results indicate that energy gains can be accomplished by the suggested layer tuning approach.Electrical and Mining EngineeringM. Tech. (Electrical Engineering